Add support to configure authentication for MCP mathod calls per API

[msm1992]

Problem

• As of now, authentication for all MCP methods is enabled by default with the below server level configuration. This config applies to all MCP APIs in the server and currently there is no way to control this at API level.

[apim.mcp]
enforce_auth_for_all_mcp_methods: true

Proposed Solution

• Introduce an API level config in publisher to enable/disable authentication for MCP method calls.
• Check the config and enforce/skip authentication for MCP requests at Auth Handler level.

Alternatives

No response

Version

No response